Auto merge of rust-lang#822 - upsuper:mangling-fix, r=emilio

Stop Rust from prepending underscore before '?' for win32

This fixes rust-lang#819.

It also includes tests for different platforms which are not supposed to be affected, so that we won't regress them in the future either.

The prefix `\x01` char is necessary for Win32. See also [msvc32_symbolify function in regen_atoms.py](https://github.com/servo/servo/blob/1b6d29e31996c87218352b825aa93e01909a6a24/components/style/gecko/regen_atoms.py#L35-L38).

src/ir/function.rs

@@ -130,7 +130,14 @@ fn get_abi(cc: CXCallingConv) -> Abi {
 
 fn mangling_hack_if_needed(ctx: &BindgenContext, symbol: &mut String) {
     if ctx.needs_mangling_hack() {
-        symbol.remove(0);
+        match symbol.chars().next().unwrap() {
+            // Stripping leading underscore for all names on Darwin and
+            // C linkage functions on Win32.
+            '_' => { symbol.remove(0); }
+            // Stop Rust from prepending underscore for variables on Win32.
+            '?' => { symbol.insert(0, '\x01'); }
+            _ => {}
+        }
     }
 }
 

tests/expectations/tests/mangling-linux32.rs

@@ -0,0 +1,28 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+
+extern "C" {
+    pub fn foo();
+}
+#[repr(C)]
+#[derive(Debug, Default, Copy)]
+pub struct Foo {
+    pub _address: u8,
+}
+extern "C" {
+    #[link_name = "_ZN3Foo4sBarE"]
+    pub static mut Foo_sBar: bool;
+}
+#[test]
+fn bindgen_test_layout_Foo() {
+    assert_eq!(::std::mem::size_of::<Foo>() , 1usize , concat ! (
+               "Size of: " , stringify ! ( Foo ) ));
+    assert_eq! (::std::mem::align_of::<Foo>() , 1usize , concat ! (
+                "Alignment of " , stringify ! ( Foo ) ));
+}
+impl Clone for Foo {
+    fn clone(&self) -> Self { *self }
+}

tests/expectations/tests/mangling-linux64.rs

@@ -0,0 +1,28 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+
+extern "C" {
+    pub fn foo();
+}
+#[repr(C)]
+#[derive(Debug, Default, Copy)]
+pub struct Foo {
+    pub _address: u8,
+}
+extern "C" {
+    #[link_name = "_ZN3Foo4sBarE"]
+    pub static mut Foo_sBar: bool;
+}
+#[test]
+fn bindgen_test_layout_Foo() {
+    assert_eq!(::std::mem::size_of::<Foo>() , 1usize , concat ! (
+               "Size of: " , stringify ! ( Foo ) ));
+    assert_eq! (::std::mem::align_of::<Foo>() , 1usize , concat ! (
+                "Alignment of " , stringify ! ( Foo ) ));
+}
+impl Clone for Foo {
+    fn clone(&self) -> Self { *self }
+}

tests/expectations/tests/mangling-macos.rs

@@ -7,3 +7,22 @@
 extern "C" {
     pub fn foo();
 }
+#[repr(C)]
+#[derive(Debug, Default, Copy)]
+pub struct Foo {
+    pub _address: u8,
+}
+extern "C" {
+    #[link_name = "_ZN3Foo4sBarE"]
+    pub static mut Foo_sBar: bool;
+}
+#[test]
+fn bindgen_test_layout_Foo() {
+    assert_eq!(::std::mem::size_of::<Foo>() , 1usize , concat ! (
+               "Size of: " , stringify ! ( Foo ) ));
+    assert_eq! (::std::mem::align_of::<Foo>() , 1usize , concat ! (
+                "Alignment of " , stringify ! ( Foo ) ));
+}
+impl Clone for Foo {
+    fn clone(&self) -> Self { *self }
+}

tests/expectations/tests/mangling-win32.rs

@@ -7,3 +7,22 @@
 extern "C" {
     pub fn foo();
 }
+#[repr(C)]
+#[derive(Debug, Default, Copy)]
+pub struct Foo {
+    pub _address: u8,
+}
+extern "C" {
+    #[link_name = "\u{1}?sBar@Foo@@2_NA"]
+    pub static mut Foo_sBar: bool;
+}
+#[test]
+fn bindgen_test_layout_Foo() {
+    assert_eq!(::std::mem::size_of::<Foo>() , 1usize , concat ! (
+               "Size of: " , stringify ! ( Foo ) ));
+    assert_eq! (::std::mem::align_of::<Foo>() , 1usize , concat ! (
+                "Alignment of " , stringify ! ( Foo ) ));
+}
+impl Clone for Foo {
+    fn clone(&self) -> Self { *self }
+}

tests/expectations/tests/mangling-win64.rs

@@ -0,0 +1,28 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+
+extern "C" {
+    pub fn foo();
+}
+#[repr(C)]
+#[derive(Debug, Default, Copy)]
+pub struct Foo {
+    pub _address: u8,
+}
+extern "C" {
+    #[link_name = "?sBar@Foo@@2_NA"]
+    pub static mut Foo_sBar: bool;
+}
+#[test]
+fn bindgen_test_layout_Foo() {
+    assert_eq!(::std::mem::size_of::<Foo>() , 1usize , concat ! (
+               "Size of: " , stringify ! ( Foo ) ));
+    assert_eq! (::std::mem::align_of::<Foo>() , 1usize , concat ! (
+                "Alignment of " , stringify ! ( Foo ) ));
+}
+impl Clone for Foo {
+    fn clone(&self) -> Self { *self }
+}

tests/headers/mangling-linux32.hpp

@@ -0,0 +1,7 @@
+// bindgen-flags: -- --target=i586-unknown-linux
+
+extern "C" void foo();
+
+struct Foo {
+  static bool sBar;
+};

tests/headers/mangling-linux64.hpp

@@ -0,0 +1,7 @@
+// bindgen-flags: -- --target=x86_64-unknown-linux
+
+extern "C" void foo();
+
+struct Foo {
+  static bool sBar;
+};

tests/headers/mangling-macos.hpp

@@ -0,0 +1,7 @@
+// bindgen-flags: -- --target=x86_64-apple-darwin
+
+extern "C" void foo();
+
+struct Foo {
+  static bool sBar;
+};

tests/headers/mangling-win32.hpp

@@ -0,0 +1,7 @@
+// bindgen-flags: -- --target=i686-pc-win32
+
+extern "C" void foo();
+
+struct Foo {
+  static bool sBar;
+};

tests/headers/mangling-win64.hpp

@@ -0,0 +1,7 @@
+// bindgen-flags: -- --target=x86_64-pc-win32
+
+extern "C" void foo();
+
+struct Foo {
+  static bool sBar;
+};